Currently, installations for planishing running metal product of strip or plate type are known and generally comprise:    a frame in which are disposed a lower planishing cassette and an upper planishing cassette,    a lower drive means for driving planishing rollers of the lower cassette in rotation,    an upper drive means for driving planishing rollers of the upper cassette in rotation,    the upper and lower drive means are disposed on a first so-called “motor” side, located external to the frame, laterally in relation to a product running axis.
Particularly on both cold and hot rolling installations including a planishing or a pre-planishing, for example of “steckel mill” type (hot reversible rolling mill) or “plate mill” type (strong steel plate rolling mill), even a rough turning section of an installation of “hot strip mill” type (hot strip rolling mill), it is desirable for plate or strip products whose criteria of thickness, of flatness, of strain hardening or other mechanical properties are highly variable to be more or less planished, or even not at all.
If a planishing is not required, a first method would consist in removing the upper cassette to allow the product to pass without planishing and to use the lower cassette as a simple roller table to support the product in its passage. Consequently, the planishing rollers of the lower cassette are inappropriate for the simple function of supporting product by rolling and are very costly. It is therefore essential to prevent them from undergoing damage detrimental to their otherwise providing good planishing quality. Furthermore, the simple rolling speed of the product on the lower cassette would generally be much higher than the speed of planishing of a product (for example five times higher). This difference in speeds would also generate overheating effects or jerks and would therefore produce marks from the product on the planishing rollers, and therefore would cause an obvious degradation of the surface condition of the rollers, and therefore is detrimental to the planished product quality, which would require premature and therefore costly changes of the rollers.
One object of the present invention is to propose a metal product planishing installation that makes it possible to temporarily inhibit, and for example replace by at least one rolling-based product support structure, a functionality or a step of planishing for at least one product of a sequence of running products, without damaging the planishing installation.
This inhibition might be done for example during replacement by at least one rolling-based product support structure. It might be done reversibly to re-establish a planishing functionality or step for another subsequent product. Switching from a planishing functionality to a planishing inhibited functionality (for example rolling support functionality), or vice versa for the same product during a series of passes of this same product in the installation is also envisaged.
It is thus also necessary to perform such a planishing inhibition (and replacement of functionality for example by at least one rolling-based product support) within a fairly short time period so as not to slow the flow of arrival of the products on the planishing installation, that is without reducing the productivity of the overall installation of a line using the planishing installation. This period is estimated at the maximum to be a time interval lying between the time of departure of the tail of a first product on leaving the planishing installation (in active planishing mode) and the time of arrival of the head of a second subsequent product on entering the installation (in planishing inhibited mode).
Another object is, finally, instead of the planishing step, to be able to introduce at least one completely different functional step associated with the metallurgical method of the line, different from the step of a simple rolling-based product support given here by way of example.
To this end, a planishing installation and a method implemented by said installation are thus proposed herein.
An exemplary embodiment and application illustrating the planishing installation and the associated method according to the invention is provided using Figures described: